marvell/uboot/drivers/geu/asr_rng.c

#include <common.h>
#include <config.h>
#include <ubi_uboot.h>
#include <asm/arch/cpu.h>
#include <kgdb.h>
#include <asm/processor.h>
#include <asm/io.h>
#include <malloc.h>
#include "asr_geu.h"
#include "asr_rng.h"

static struct random_data random_data = {
    .random_base = GEU_BASE,
    .random_num_saved = 0
};

#define random_read(x)	readl(random_data.random_base + x)
#define random_write(x, y) writel(y, (random_data.random_base + x))

static void geu_rng_enable(void)
{
	uint32_t val;
	uint32_t seed = read_timer();   //TODO

	val = random_read(GEU_PRNG_CTRL_REG);
	if (!(val & GEU_PRNG_EN)) {
		val |= GEU_PRNG_EN;
		random_write(GEU_PRNG_CTRL_REG, val);
		udelay(1000); /* means a reset happens */
	}
	random_write(GEU_HW_RANDOM_NUM_SEED, seed & 0xFF);
}

static uint32_t geu_get_random_data(void)
{
	uint32_t val = 0;
	uint32_t timeout = 100, mytime;
	int ret = 0;

	uint32_t start = get_timer(0);
	
	do {
		val = random_read(GEU_HW_RANDOM_NUM_GEN);
		mytime = get_timer(start);

		if (mytime >= timeout) {
			// porintf("fail to generate rng seed, time out!");
			panic("fail to generate rng seed, time out!\n");
		}
	}while(val ==0 || val == random_data.random_num_saved);

exit:
	random_data.random_num_saved = val;

	return val;
}

uint32_t crypto_rng_read(void *buf, size_t len)
{
	uint32_t *rngbuf = buf;
	uint32_t val = 0;

	assert(buf);

	asr_geu_get();
	geu_enable_clk();
	geu_rng_enable();

	while (len) {
		val = geu_get_random_data();
		if (len > sizeof(uint32_t)) {
			len = len - sizeof(uint32_t);
			memcpy(rngbuf, &val, sizeof(uint32_t));
			rngbuf++;
		} else {
			memcpy(rngbuf, &val, len);
			len = 0;
		}
	}
	geu_disable_clk();
	asr_geu_put();

	return 0;
}

uint8_t hw_get_random_byte(void)
{
	uint8_t data = 0;

	if (crypto_rng_read(&data, 1))
		panic("rng read failed\n");

	return data;
}

uint32_t hw_get_random_32(void)
{
	uint32_t data = 0;

	if (crypto_rng_read(&data, 4))
		panic("rng read failed\n");

	return data;
}

void geu_random_test(void)
{
    uint8_t buf[32] = {0};
    uint32_t size = sizeof(buf);

    if (crypto_rng_read(buf, size)) {
        printf("geu rng test failed");
        return;
    }

    for (uint32_t i = 0; i < size; i++) {
        printf("%.2x ", buf[i]);
        if ((i + 1) == 0)
            printf("\n");
    }
    printf("\n");
}